Devices for coupling rotating shafts together are well known in the art. Primarily, existing devices are designed to couple shafts of similar diameter or to connect a shaft to another type of mechanical device. Currently existing devices are unsatisfactory in that they are not easily adaptable for use in coupling shafts of different diameter and are not easily attachable or detachable after prolonged use. The applicants device is capable of rigidly and securely coupling shafts of separate diameters while still being easily detached from the shafts and reattached for later use.
The following patents reflect the state of the art of which applicant is aware and are included herewith to discharge applicant's acknowledged duty to disclose relevant prior art. It is stipulated, however, that none of these references teach signally nor render obvious when considered in any conceivable combination the nexus of the instant invention as disclosed in greater detail hereinafter and as particularly claimed.
______________________________________ INVENTOR PATENT NO. ISSUE DATE ______________________________________ White 3,236.572 Feb. 22, 1966 Zugal 3,844,137 Oct. 29, 1974 Zugal 3,917,424 Nov. 4, 1975 Eiland et al. 4,217,061 Aug. 12, 1980 Vella 4,505,609 Mar. 19, 1985 Boogerman et al. 4,848,951 Jul. 18, 1989 ______________________________________
The patent to Eiland teaches a shaft coupling with two separate tapered keys and a groove defining two separate collars for each shaft. The Eiland patent is only capable of attaching shafts of identical or nearly identical diameter. Furthermore, the Eiland patent is weakened by the placement of the groove between the two collars reducing its torque withstanding ability. The applicant's invention is capable of fastening shafts of entirely different shaft diameter with the axis of rotation of the two shafts being co-linear rather than offset as the Eiland patent would require. The applicant's invention is not disrupted by any grooves which circumscribe the circumference of an inner bore improving its torque withstanding capability.
The two patents to Zugal teach a shaft coupling device made of plural elements; a first element to fasten to a first shaft, a second element to fasten to a second shaft, and a third element to provide a flexible linkage between the first two elements. The Zugal patents attach a sleeve to each shaft which is composed of two distinct half-circular portions held together by complemental bolts and threaded holes. The Zugal patent is not designed to form a rigid coupling between the two shafts but rather is designed for flexible attachment of two shafts which are out of line. The applicant's device, being formed without grooves perpendicular to an axis of shaft rotation, is better able to withstand high torque loads.
The remainder of the prior art further diverge from the unique attributes of the applicant's invention.